Interval timer



March 18, 1952 P. o. MELLARD 2,590,027

INTERVAL TIMER Filed Feb. 15, 1949 3 Sheets-Sheet 1 IN V EN TOR.

PRATHER O.MELLARD BY ATTORNEY March 18, 1952 P. o. MELLARD 2,590,027

INTERVAL TIMER Filed Feb. 15, 1949 5 Sheets-Sheet 2 IN V EN TOR.

\PRATHER 0.MELLARD BY ATZOB/VEY March 18, 1952 p Q, MELLARD 2,590,027

INTERVAL TIMER Filed Feb. 15, 1949 3 Sheets-Sheet 5 INV EN TOR.

RATHERQMELLARD Patented Mar. 18, 1952 INTERVAL TIMER Prather '0. Mellard, Philadelphia, Pa., assignor of one-half to Morris M. Marks, Oreland, Pa.

Application February 15, 1949, Serial No. 76,577

17 Claims.

My invention relates to interval timers, and it relates more particularly to means for announcing elapsed time, which may be set and operated without visual aid.

In certain fields of endeavor, as for instance in photographic dark rooms, it is required to utilize an interval timer which must operate in the dark. Such timers consist of a means for setting the device to indicate any desired time interval, and means for indicating the elapsing of such time interval. No means are provided however, for enabling the operator to set the timer while in the dark. Thus, should a photographer during a developing process, require the use of a timer,

it is necessary for him to carefully put away his materials, turn on the light, set his timer, turn off the light, bring out his materials again, and with one hand begin the timed photographic process while simultaneously depressing the lever which starts his timer, with the other hand. As result, much time is lost in th process, spoilage may ocour and considerable dexterity is required. Moreover, should it be desirable to utilize an interval timer after a photographic process may have started, it may be impossible to do so, for it is then too late to turn on the light, to set the timer.

One object of my invention therefore is to provide an interval timer comprising means whereby the timer may be set while in the dark, for any desired time interval; and which will operate in such a manner as to enable the user thereof to be free to apply both hands to the starting of the photographic process at the commencement of said time interval.

Another object of my invention is to provide means whereby various time intervals may be indicated to the operator without the use of light.

A further object of my invention is to provide an interval timer which is simple and inexpensive to construct, certain in operation and easy to use.

Other objects of my invention will appear from the drawings and the further description thereof which follows, as well as the appended claims.

With the above and other objects in view, my invention consists of an interval timer comprising a clock mechanism, a time set, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a sound-actuating device; said clutch mechanism comprising means for selectively engaging said clock mechanism in a manner to permit said clock mechanism to operate said shaft, and

for disengaging said clock mechanism therefrom during the setting operation of said shaft; a brake disposed between said time set and a portion of said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition and said clutch is engaged with said clock mechanism, and for engaging said brake with said portion of said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a time indicator representing the termination of a time interval, and a time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device when said time set is moved in setting operation, and said first-mentioned time indicator being actuated by said sound actuating device when said shaft has been moved by said clock mechanism through the time interval for which said time set has been set.

My invention also consists of an interval timer comprising a plurality of audible time indicatin devices, each of which has a characteristic sound indicating a specific time interval.

My invention further consists of an interval timer comprising audible time indicating devices which can be selectively disposed in operating and non-operating condition without the use of visual aid.

My invention also consists of an interval timer comprising an audible time indicator representing the termination of a time interval, and an audible time indicator representing the commencement of a time interval, both of said time indicators being actuated by a sound actuating device connected with a time set, and the second-mentioned time-indicator being actuated into sound during the setting operation of said time set, and again actuated into sound at the commencement of said time interval, the time lapse between both of said actuations of said indicators being substantially suiiicient for a warning that said time interval is about to start.

For the purpose of illustrating my invention, I have shown in the accompanying drawings forms thereof which are at present preferred by me, since the same have been found i practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the practice arrangements and organizations of the instrumentalities time indicating device 2 Figure 1 represents a front elevational view of an interval timer embodying my invention, with the outside case thereof removed.

Figure 2 represents an enlarged, rear elevational view of an interval timer' mechanism embodying my invention, with the outside case thereof removed.

Figure 3 represents aside elevational view of the interval timer mechanism illustrated in Figure 2.

Figure 4 represents an enlarged, perspective view of a portion of the braking mechanism of an interval timer embodying my invention.

Figure 5 represents a sectional view, taken from the rear, of an interval timer, embodying my invention, and taken generally along the lines 5-5 of Figure 3.

Figure 6 represents a sectional view taken generally along the lines 5-8 of Figure 2.

Figure '7 represents an extended perspective view of a sound actuating device forming part of an interval timer embodying my invention.

' hand set mechanism illustrated in time interval setting operation.

Figure 12 represents a rear elevational view of the interval timer mechanism illustrated in Figure 11, with the mechanism illustrated in time interval measuring operation.

Figure 13 represents a side elevational view of the interval timer mechanism illustrated in Figure 11.

-According to my invention I provide an interval timer 20 comprising a clock mechanism 2 i, a time set 22, a brake means 23 and an audible The clock mechanism 2| comprises any standard clock device, and for illustrative purposes only, I have shown herein a spring-type clock mechanism comprising a 'main spring 25, train of gears 2%, balance wheel 7 21, hair-spring 28, escapement 29, and main or minute-hand shaft 30.

The shaft 3!) comprises part of a time set assembly 31, comprising a knob or other suitable handle 32, shaft 39 and clutch The shaft 30 is preferably journaled in the rear plate 3 of the clock mechanism 2!, and in a preferred form of my invention extends beyond said plate 34 and through a base plate 35 which is preferably mounted on bolts 35 which pass through the posts 31. Suitable spacer members 33 are disposed about said bolts 36 and between the rear plate 34 and base plate Suitable nuts 39 or other appropriate retaining means secure the base plate 35 to the bolt 35 in spaced relation to the rear plate 35 of the clock mechanism 2|.

For purposes of illustration only, and without limiting my invention thereto, I have shown in the drawings a clock mechanism 2! having a dial 4!] and hands ll and 42, which can be read by visual means, as auxiliary to the audible time indicating means which will be further described hereinafter, although it is to be understood that my invention is capable of being operated entirely without the aid of visible means. According to the means thus illustrated, there is provided a main or minute hand All mounted on the main shaft 30, and which makes a complete revolution about the dial it every ten minutes, and a secondary hand 42 mounted on a secondary shaft s6 which is geared to the shaft 3Q by a suitable train t3, and which makes a complete revolution about the dial every two hours; although it is to be understood that any other desired arrangement of trains, hands and dials can be provided, for recording any desired time interval or groups of time intervals of any length or relationship of main or minute hand and secondary hand, without departing from the spirit or essential attributes of my invention.

In a preferred form of my invention, I provide a brake means 23 for stopping the operation of the clock mechanism 2! at the completion of the time interval to be measured. Various forms of brake means may be used, and for purposes of illustration only, I have shown a cam is mounted on the main hand shaft 35, and a similar cam 45 mounted on the secondary hand shaft it. The cams 5 3 and preferably each comprise a high portion ll extending over a major portion of their periphery, and a low portion 48. A cam follower s9 is preferably formed at one end of a bell crank 59 pivoted on a shaft 5!, and urged against the peripheral faces of the cams it and 45 by a suitable spring 52. The opposite arm 5-3 of the bell crank 59 carries a brake arm 56 which may be in the form of a spring wire which is adapted to be urged against, and to bear upon, the balance wheel 27 when the bell crank 56 is tilted toward the low portions of the cams i i and 35 by means of the spring 52 bearing against the bell crank 5t when the low portions 48 of said cams are in registry with the cam follower 49. In practice, the low portions 48 of the cams it and 45 are so arranged on their respective shafts 39 and 46 that th y will be in apposition to the cam follower A9 when the shafts 39 and 45 have been rotated by the clock mechanism and. trains to the position in which they would be when time interval is elapsed.

In cases where dial as and hands 4i and iz are used, this condition will have been achieved when the minute hand (ll points to 10 and the secondary hand t2 points to 120, on the dial shown in Figure 1. It will be noted that the dial face 4i} comprises two dial registers 55 and 55; the dial register 55 containing indicia for measuring units of one minute each, and including "fractional parts of a minute, to a total of 10 minutes for each revolution of the hand ll about the face of the dial 46; and the dial register 56 containing indicia for measuring units of 10 minutes each, each unit representing one complete revolution about the dial by the hand it, and said indicia totalling 12 such revolutions, or minutes for each complete revolution of the secondary hand 42. Thus, the time interval is indicated as follows: the secondary hand s2 is consulted to determine the number of minutes on the dial register 56 to which it is pointing. When it is pointing to an area between indicia on the dial register 56, the smaller of the two indicia is to be consulted, and in such cases the numeral 120 is to be considered as 0. The minute hand M is then to be consulted, and the number of minutes and fractional parts thereof, to which it points on the dial register 55 is to be added to the number of minutes indicated by the secondary hand 42, it being remembered that when the hand 42 points to less than 10, the index on the dial 55 is to be taken as 0. Thus, for instance, when the hands are in the position indicated in Figure l, the time interval to be measured is 10 minutes. Should the secondary hand be pointing instead to number 36 on the dial register 56, the time interval would be minutes; whereas, should the secondary hand 42 be pointing to 120, it would indicate that since both hands 4|, 42, are pointing to the equivalent of zero, the time interval will have elapsed.

It will thus be observed that in all instances in which either the hand 4| or the hand 42 are pointing to other than 10 or 120, respectively, there will be a high portion of the cam 44 or the cam 45, or both, bearing against the cam follower 49, thereb urging the brake 54 away from the balance wheel 21, operably to permit the balance wheel 21 to operate in time-measuring movement; but when the low portions 48 of both cams 44 and are in apposition to the cam follower 49, and this will occur only when the hand 4! points to 10, and the hand 42 points to 126, the bell crank 5|! will rock by virtue of the spring, 52 bearing thereagainst, and the brake 54 will be applied against the balance wheel 21 to bring the clock mechanism to an immediate stop.

The shaft 30 preferably projects beyond the r base plate 35 a suitable distance, and a trip arm 51 projects laterally therefrom, and preferably substantially parallel to the base plate 35. Suitable sounding devices are disposed about the shaft 30 on the base plate 35, and may take the form of musical reeds 58 formed of any suitable material such as brass, steel, or the like, each mounted at one end, in a stud 59 which is secured to the base plate 35 by any suitable means such as a bolt 60 and lock-nuts 6|. The reeds 58 project from the studs 59 in a manner to be free to vibrate when they are released after engagement with the trip arm 51. In a preferred form of my invention, the reeds 58 are each of a different sound pitch, and are disposed about the base plate 35, with their free ends 62 forming a circle in spaced relation to the shaft 33 and concentric therewith, and within the area traversed by the revolution of the trip arm 51 about the axis of the shaft 30.

Moreover, in a preferred form of my invention, the reeds 58 are identical in number to the number of minutes it takes for the shaft 31] to make one complete revolution, and one of the reeds 58 is so disposed with relation to the trip arm 51, that when said arm 51 engages the reed during the time interval-measuring operation, this reed 63 will be released at the instant the measured time interval will have elapsed; and each of the free ends of the other reeds 58 are preferably so disposed about said shaft 30 with relation to the trip arm 51, that said arm 5'! will, during the time-measuring rotation of the shaft 38, engage the free end 62 thereof and release it at the exact moment when one of the measured minutes will have elapsed; there being one read for each of the minutes to be measured in the complete rotation of said shaft 30.

One form of such time measuring device is illustrated in Figure 2, wherein the free ends 52 are disposed equidistantly about a circle co-axial with the shaft 30, and the stud ends of the reeds 58 are disposed equidistantly about a circle which is eccentric to the shaft 30, the reeds being of substantially the same thickness, width and texture, but of varying lengths as required by the two circles. In this manner, the reeds will each evoke a sound of a different pitch from any other reed in the mechanism, and this pitch can be recognized and sought when the minute which it represents is being indicated by the movement by the shaft 30 causing the trip arm 51 to engage and release said reed into soundemitting vibration.

A clutch 33, of any suitable construction is disposed between the clock mechanism 2| and the shaft 30, such that when the time set 3| is turned in a manner to set the interval timer, this can be done without substantial interference with the clock mechanism 2|. This setting operation is preferably performed in a counter-clockwise direction with respect to the dial 49, which would render it a clockwise direction with respect to the rearwardly viewed base plate 35. The clutch mechanism 33 also permits the clock mechanism 2| to drive the shaft 3|] when the time set handle 32 is released. This motion of the shaft 30 is preferably clockwise with respect to the dial 40, and counter-clockwise with respect to the rearwardly viewed base plate 35. Thus, in the embodiment of my invention illustrated in Figures 1 to '7 inclusive, the trip arm 51 will move about the base plate 35 in a clockwise direction when the interval timer is being set, and will move about said base plate in a counter-clockwise direction when the time interval is being measured.

In operation, when the interval timer is being set, the time set handle 32 is grasped and turned in time setting direction. This causes the trip arm 57 to revolve about the base plate 35, and virtually silently to engage the reeds 58 ad seriatim, and to release each reed after it has been deflected an appreciable distance beyond its point of initial engagement with the trip arm 51. Thus,

I upon its release, the reed will emit a sound ac cording to a given pitch. This sound will warn the operator that the interval timer has now been set for a time interval of at least the number of minutes indicated by the reed whose sound has just been emitted. When this is the same number of minutes that the operator wishes to measure, he releases his hold on the time set handle 32. In the meantime, the cams 44, 45 have been rotated in a manner to release the brake 54, and when the handle 32 is released, the clock mechanism 2| is free to rotate the shaft 30 by means of the clutch 33. The operator is now free to use both hands to start any desired operation Whose time is to be measured by the interval timer. Such operation could for instance, be the development or printing of a pictiu'e in a dark room. The operator, having thus been warned during the time setting operation, by the sounding of the appropriate note for the given minute which begins the time interval he wishes to measure, now holds himself in readiness to start his photographic or other operation as soon as he hears that same note sounded again. It will be observed that, according to my invention, the trip arm 51 will release any given reed during the setting operation, and will by the operation of the clock mechanism 2| re-engage that reed and release said self-same reed a short time later at the exact commencement of the time interval to be measured. The time lapse between the two sounds of the same reed gives the operator sufficient time to release his hold of the interval timer, turn to whatever operation he is performing, and be ready to start that operation the instant of the second sounding of that reed.

In setting, the operator can measure the time interval either by counting the number of sounds emitted by the reeds during the setting operation of the device, or he can learn to recognize the minutes indicated b the characteristic note emitted by each of these reeds. Thus, the reeds 58 may be so provided that do may indicate one minute, re may indicate two minutes, mi may indicate three minutes, and so on. In either event, having thus determined that the interval timer is now set for a given number of minutes, and having released the time set handle 32, the operator can determine the elapsing of the measured time interval in the same manner. In addition, the brake 23 will prevent the further rotation of the shaft upon the termination of the measured time interval, and the ceasing of operation of the clock mechanism 2! and of the audible time indicating mechanism A l, serve as additional audibly recognizable indicia of the elapsing of the measured time interval.

If desired, a second set of reeds (not shown) may be employed, pitched at a diiferent octave, and substantially similarly disposed about the shaft 30 in a manner to be plucked by the same or a different trip arm as the arm 57, with the reeds so disposed about the shaft 35! as to be released by the trip arm at any desired position with relation to the time interval to be measured. Thus, for instance, by the utilization of such a secondary set of reeds (not shown), the operator can be informed by the sounding of such a reed, that the shaft 30 is now at the exact position where it is ready to begin a given measured time interval.

In Figure 8 is illustrated a modified construction of time indicating mechanism comprised in an interval timer embodying my invention. In this construction, I provide a sounding device, such as a reed 64, anchored at one end in the sleeve 65 slidably mounted on the post 66 which is anchored to the base plate 35 by any suitable means such as the bolt Bl and lock nuts St. A pin 69 projects from the side of the post 55, and rides in a longitudinal slot 70 formed in the sleeve 65. A handle member .l is formed on the rearwardmost end of the sleeve 65. The internal diameter of the sleeve 65 is preferably substantially equal to the external diameter of the post 66 so as to provide a substantially close fit between the two. The reed 64 projects from the sleeve 65 into the path of the trip arm 51 of the shaft 30, when the sleeve 65 is in forwardmost position, and is withdrawn from the path of said trip arm 51 when the sleeve is drawn into rearwardmost position by means of the handle H. Thus, the operator can withdraw from sounding operation any chosen time indicating reed, at will.

In this manner, when the interval timer is equipped with audible time indicating members of this or similar construction, the operator can count the number of minutes he wishes to measure, by running his finger along the handle members H. If desired, he can pull these handle members ll outwardly as he counts them. When he has thus withdrawn from operative range, all reeds 64 between the reed representing the beginning of the desired time interval, and the reed representing the end thereof, he then turns the time set handle 32 until the trip arm Si intercepts and releases the first reed 64 within its path, thereby vibrating said reed. This warns the operator that the interval timer is now ready to measure the desired time interval. He then releases his hold on the handle 32, thereby permitting the clock mechanism to rotate the shaft 30 until the trip arm 51 again intercepts and releases said reed 64. The sound emitted by the vibration of this reed 64 notifies the operator that the desired time interval has begun to be measured. The next sound emitted by a vibrating reed will be the terminal sound, notifyin the operator that the interval has just then elapsed. If desired, the operator can permit the next to last reed to remain within the path of the trip arm 5i, so as to warn him that the interval is about to terminate. Or, he may leave selected reeds within the path of the trip arm 51, to inform him of the arrival of certain selected portions of the time interval, as may be desired.

In Figures 9 and 10 are illustrated another modified construction of interval timer, embodying my invention. In this construction, I provide an auxiliary sounding device such, for instance, as the bell 12 mounted on the base plate 35, and which is capable of being struck by a clapper it carried by the lever 14 pivoted as at E5 to the base plate 35, intermediate the clapper l3 and a stud l6 disposed generally at the opposed end of the lever M. In a preferred form of my invention, I provide auxiliary devices for strengthening the strike of the clapper 13 against the bell l2, and quickly to withdraw said clapper l3 therefrom in order to enhance the resonance of the bell 12. Thus, for instance, I may provide a spring 'l'l mounted on the lever 14 and anchored on the pivot 15, operably to urge the clapper 73 toward the bell 12. A leaf spring buffer stop 78 is mounted on the base plate 35 intermediate the pivot 15 and the bell l2, and is adapted to be engaged and deflected by the lever i l just before the completion of the stroke of the clapper l3 against the bell 12; but yieldingly to hold the lever 74 against striking engagement with the bell, when the lever 14 is at rest.

In one form (not shown) of my invention, the stud 16 may be in the path of travel of the trip arm 5?, in which case it will be intercepted by the trip arm 51 in the setting operation, there-' by to urge the lever 14 against the buffer stop 78, until the stud I6 is swung out of the way, whereupon the spring buffer 78 recoils to rock the lever and stud it back into the path of the trip arm 5'? for operative engagement during the time measuring revolution thereof. Or, in another form of my invention, the stud 76 may engage and be actuated by the deflection of the reed 63, during the time measuring rotation of the shaft 30. In either of these forms, the counter-clockwise sweep of the trip arm 51 in the time measuring rotation of the shaft 36 will cause the stud 16 to be, engaged and carried in the same direction until its release by the continued sweep of the trip arm 51. In this movement of the stud It, the lever 14 is rocked about the pivot 15 against the increasing resistance of the spring ll. Immediately upon its release, the lever 14 is swung in a reverse direction about the pivot 15 by virtue of the tension of the spring ll, until the leading edge of upper portion of the lever 74 engages and deflects the spring buffer l8 and the clapper l5 strikes the bell E2. The deflected buffer lB thereupon instantly recoils, carrying with it the clapper end of the lever M, thereby immediately to withdraw the clapper from any possible sound-dampening contact with the bell 12. The bell 12 is thus sharply rung and allowed to resonate.

In a preferred form of this embodiment of my invention, the bell I2 and stud 16 are so disposed as to cause said bell to be struck at the moment when the measured time interval has terminated. However, if desired, the bell and stud may be so disposed as to indicate any other desired lapse of time. In the embodiment of my invention illustrated in Figure 9, I have illustrated a reed 63 indicating the location of the terminus of the measured time interval, for setting purposes. The position of the reed 63 in its non-engaged condition is indicated at 19, and it will be understood that during the setting operation it will be released into soundemitting vibration at a point on the opposite side from that illustrated in Figure 9. Thus, the operator may be warned of the location of said terminus by virtue of the reed B3, in the setting operation of the interval timer? whereas the bell I2 will ring when the terminus has actually been reached in the time measuring operation. In operation, the reeds 58 will be engaged and released by the trip arm 51 in the course of setting the interval timer and again engaged and released by said arm 51 in the course of time measurement. The operator is informed of the progress of the actual time being measured, by the different notes emitted by the reeds 58 and is notified of the actual termination of the time interval by the ringing of the bell I2.

In Figures ll, 12 and 13 are illustrated another modified construction of interval timer embodying my invention. In this construction, clock mechanism 80 of substantially the same construction as the clock mechanism 2 I, is utilized. Moreover, a time set SI of substantially similar construction as the time set 3|, is used. This time set comprises a shaft 82 projecting rearwardly of a base plate 83 mounted on the posts 84 similarly to the mounting of the base plate 35 on the posts 37. A trip arm 85 projects laterally from the shaft 82, preferably substantially parallel to the base plate 83. Reeds 85 are mounted on the base plate 83, with their free ends projecting into the path of travel of the trip arm 85, in a manner substantially similar to that of the reeds 58; and the reeds 86 are preferably similarly tuned. If desired, the reeds 86 may be anchored in posts similar to the post 59 in Figure 7, the sleeves 65 of Figure 8 or other mounting means may be utilized such for instance as the annulus 81 which is mounted on the base plate 83 by means of rivets 88 or other suitable means. As illustrated in Figure 11, the reeds 86 are disposed in suitable slots I06 in the annulus 87, with one end of each reed bent over and bearing against the outer peripheral face 89 of the annulus, to which it is secured by means of screws, rivets St, or the like. The free end of the reed 88 projects interiorly of the annulus in a manner to space said free ends equidistantly about a circle concentric with the shaft 82. The annulus is preferably disposed on the base plate 83, eccentric to said shaft 82, thereby to provide for varying lengths of the reeds 86, operably to give them diverse sound pitches. If desired, suitable legends, such as the numerals It? may be disposed about the outer face I08 of the annulus, with each in apposition to a respective reed 86; thereby to form a dial which operates in conjunction with the trip arm 85 as a hand, to which the numerals I01 lead by means of said reeds '86. Such a dial would provide auxiliary visual time indicating means if such is desired,

' the dial I98.

10 and in such event could supplant the dial 40 and hands 4| and 42.

A suitable alarm mechanism 9I is disposed in conjunction with the clock mechanism 80, and may comprise generally a clapper 92 carried by a clapper arm 93 mounted on a pallet 94 which operates on an escapement wheel SE5 powered by a spring actuated train 96. This spring is preferably wound by means of a crank lever 91 fixedly mounted on the spring shaft 98, and which traverses a path from the position illustrated in Figure 11 to that illustrated in Figure 12, during the winding operation, and traverses a path from that illustrated in Figure 12 to that illustrated in Figure 11 during the unwinding or alarm-ringing" operation. Suitable cams 99 and I00 are preferably mounted on the time set BI in substantially the same relation to said time set as the cams 4I bear to the time set 3I. A suitable cam follower IGI rides on said cams es and I90, and is fixedly secured to the pallet ea operably to prevent operation of the escapement 95 when a high portion of either cam is bearing against the follower IilI and to permit the rocking of said pallet with respect to said escapement wheel 95, when the low portions of both cams 59 and I50 are in registry with the follower IIH This, as has been hitherto explained, will occur when the main shaft 82 and the secondary shaft I92 are both in the position where no further time interval is to be recorded.

'A brake I63 disengageably' bears against the balance wheel I64 in a manner already described with relation to the brake 54 and balance wheel 27. The brake I93 is preferably actuated in any suitable manner by an operation of the alarm mechanism, such for instance as by a cam (not shown) carried by the spring shaft 98, bearing against the brake arm I05 and rocking the same to cause the brake I03 to bear against the balance wheel I04 when the crank lever 91 is swung from the position illustrated at H19 in Figure 12, to that indicated at III] therein. In such case, the brake I03 may be released from engagement with the balance wheel I04 by the operation of a suitable spring IiI mounted on the pivot II2 about which the brake arm I95 rocks, and said spring bearing against said arm to lift it away from braking engagement with the balance wheel I04.

In operation, when it is desired to set this form of interval timer of my invention, the crank lever 97 is cranked from the position IIO to the position I09, thereby winding the alarm spring mechanism 95; and the time set BI is then grasped and turned in a clockwise direction with respect to In so doing, the reeds 86 are engaged ad seriatim, and released as at I I3, thereby emitting sounds of pitches preferably variant according to the minutes to be indicated. When the proper number of reeds has been thus plucked, or the appropriately pitched reed has been sounded, thereby informing the operator that the interval timer is now set for the number of minutes he wishes to measure, the operator releases his hold on the time set SI and turns his attention to the operation which he wishes to time. The cranking of the lever 97 having, as hereinbefore described, simultaneously released the brake I63 from the balance Wheel II4, the clock mechanism 83 commences to operate, and upon the release of the time set by the operator, the clutch engages and the main shaft 82 rotates in the direction indicated at H4 in Figure 12. In so doing, the trip arm re-engages the reeds 8'6 and releases them into sound emitting vibrations at one minute intervals, as for instance when the reed H is engaged as at H6, and released in the position shown at I 55. In all revolutions of the trip arm 85 prior to the terminal revolution, the cam follower lill will ride upon a high portion of one, or the other, or both, of the cams 98, N39; and the passage of each time interval indicated by the numeral will be announced by the sounding of its appropriate reed. However, when the trip arm 85 is traversing its terminal rotation, the low points of both cams 99 and I09 will be juxtaposed to the cam follower lill when the time interval has fully elapsed. This permits the cam follower [iii to drop into the low portions of the cams t9, I89, sufiiciently for the pallet 9a to rock within the escapement 95 under the urging of the spring mechanism 96, thereby to vibrate the clapper arm 93 and to cause its clapper 92 to strike against any appropriate sounding device, such as a bell (not shown). To aid in this, a suitable spring H'l may be utilized, anchored at one end H8 in the plate 83, and at the other end in the clapper arm 93. The termination of the time interval is thus announced by the ringing of the bell, or otherwise by the operation of said alarm mechanism. If desired, suitable auxiliary time indicating means, such for instance as the mechanism illustrated in Figures 9 and 10, may be provided for indicating various portions of the time interval, in a manner already described.

It will thus be seen, that by my invention, I have provided mechanism whereby an interval timer may readily be set entirely without visual aid, and whereby its interval timing operation will commence without the use of human hands and without diverting the operators attention from the operation which he wishes to time. Moreover, various time intervals are indicated to inform the operator of the fractional passage of time within the total interval, and to warn him of the approach of the terminus of the timed interval. Not only so, but means are provided whereby the operator may be informed at any given fractional time interval, of the identity of such time interval, and auxiliary alarm means are provided for announcing the arrival of specific portions of such time interval; and all of the foregoing is provided without resort to visual aid.

It will be understood that in all the modifications of my invention, the reeds, bells and other sounding devices may be interchanged, and may also be used to indicate fractional time intervals of other than one minute, as desired.

, I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiments to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a sound-actuating device adapted to be moved in one direction during time setting operation, arid in another direction during interval timing operation; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart motion to said shaft during interval timing operation, and for disengaging said clock mechanism therefrom during the setting operation of said shaft; a brake disposed between said time set and said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition and said clutch is engaging said shaft with said clock mechanism, and to engage said brake with said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a sound-emitting time indicator representing the commencement of a time interval, said lastmentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said firstmentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; and means selectively to Withdraw an audible time indicating device from sound emitting engagement with said sound-actuating device.

2. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart motion to said shaft during interval timing operation, and for disengaging said clock mechanism therefrom during the setting operation of said shaft; a brake disposed between said time set and said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition and said clutch is engaging said shaft with said clock mechanism, and to engage said brake with said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a sound-emitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

3. An interval timer comprising a. clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; said clutch mechanism comprising means for selectively engaging said 13 clock mechanism with said shaft operably to permit said clock mechanism to impart motion to said shaft during interval timing operation, and for disengaging said clock mechanism therefrom during the setting operation of said shaft: a brake disposed between said time set and said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition and said clutch is engaging said shaft with said clock mechanism, and to engage said brake with said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a soundemitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof.

4. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set compris ing a handle portion, a shaft, clutch mechanism, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart motion to said shaft during interval timing operation, and for disengaging said clock mechanism therefrom during the setting operation of said shaft; a brake disposed between said time set and said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition and said clutch is engaging said shaft with said clock mechanism, and to engage said brake with said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a soundemitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting.operation movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; and means selectively to withdraw an audible time indicating device from sound emitting engagement with said sound-actuating device.

5. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart motion to said shaft during interval timing operation,

and for disengaging said clock mechanism there-' from during the setting operation of said shaft; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a soundemitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; and means selectively to withdraw an audible time indicating device from sound emitting engagement with said sound-actuating device.

6. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, and a soundactuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; means disposed between said clock mechanism and said sound actuating device to transmit motion from said clock mechanism to said sound actuating device during said interval timing operation; said audible time indicat ing devices comprising a sound-emitting time indicator representing the termination of a time interval, and a sound-emitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; and means selectively to withdraw an audible time indicating device from sound emitting engagement with said sound-actuating device.

'7. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, and a soundactuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; means disposed between said clock mechanism and said sound actuating device to transmit motion from said clock mechanism to said sound actuating device during said interval timing operation; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of atime interval, and a sound-emitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation'movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof.

8. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; means disposed between said clock mechanism and said sound actuating device to transmit motion from said clock mechanism to said sound actuating device during said interval timing operation; a brake disposed between said time set and said clock mechanism; means to release said brake when said time set has been disposed in time interval setting condition, and to engage said brake with said clock mechanism when said time interval is elapsed; said audible time indicating devices comprising a soundemitting time indicator representing the termination of a time interval, and a sound-emitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

9. An interval timer comprising a clock mechanism, a time set, and a plurality of audible time indicating devices; said time set comprising a handle portion, a shaft, and a sound-actuating device adapted to be moved in one direction during time setting operation, and in another direction during interval timing operation; means disposed between said clock mechanism and said sound actuating device to transmit motion from said clock mechanism to said sound actuating device during said interval timing operation; said audible time indicating devices comprising a sound-emitting time indicator representing the termination of a time interval, and a sound-emitting time indicator representing the commencement of a time interval, said last-mentioned time indicator being actuated by said sound actuating device during said setting operation movement thereof, and again actuated by said sound-actuating device in the course of said interval timing movement thereof, and said first-mentioned time indicator being actuated by said sound-actuating device in the course of said interval timing movement thereof; and means selectively to withdraw an audible time indicating device from sound emitting engagement with said sound-actuating device.

10. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said brake mechanism comprising a brake adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices comprising reeds mounted on said interval timer and disposed with free ends thereof intercepting the path of said sound-actuating arm; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

11. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said brake mechanism comprising a brake adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices each comprising reeds fixedly mounted on, and projecting from, a movable base; said base being substantially fixed in one position, and movable to another position, at will, thereby to dispose the free end of at least one of said reeds selectively within, and outside of, the path of said sound-actuating arm; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

12. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit .said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said brakemechanism comprising a brake adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices each comprising reeds fixedly mounted on, and projecting from, a movable base; said base being substantially fixed in one position, and movable to another position, at will, thereby to dispose the free end of at least one of said reeds selectively within, and outside of, the .path of said sound-actuating arm.

13. An interval timer comprising a clock mechanism, a time set, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said audible time indicating devices comprising reeds mounted on said interval timer and disposed with free ends 17 thereof intercepting the path of said soundactuating arm; each of said audible time indicating devices having a characteristic sound indica tive of a specific time interval.

14. An interval timer comprising clock mechanism, a time set, and audible time indicating devices; said time set comprising a handle portion, shaft, and a revolving sound actuating arm connected to said shaft; means disposed between said clock mechanism and said sound acuating arm to transmit motion from said clock mechanism to said sound actuating arm; said audible time indicating devices comprising reeds mounted on said interval timer and'disposed with free ends thereof intercepting the path of said sound-actuating arm; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

15. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, and a revolving sound actuating arm connected to said shaft; means disposed between said clock mechanism and said sound actuating arm to transmit motion from said clock mechanism to said sound actuating arm; said brake mechanism comprising a brake adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices comprising reeds mounted on said interval timer and disposed with free ends thereof intercepting the path of said sound-actuating arm; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval.

16. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft operably to permit said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said brake mechaism comprising a brake iii adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices comprising a bell-ringing assembly and reeds, said reeds mounted on said interval timer and disposed with free ends thereof intercepting the path of said sound-actuating arm; each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; and means for actuating said bell-ringing assembly at a given stage of time-indication.

17. An interval timer comprising a clock mechanism, a time set, brake mechanism, and audible time indicating devices; said time set comprising a handle portion, a shaft, clutch mechanism, and a revolving sound actuating arm connected to said shaft; said clutch mechanism comprising means for selectively engaging said clock mechanism with said shaft oper ably to permit said clock mechanism to impart rotation to said shaft in one direction, and for disengaging said clock mechanism from said shaft during rotation of said shaft in another direction; said brake mechanism comprising a brake adapted to engage, and suspend movement of, said clock mechanism at the termination of a time interval, and to release said clock mechanism during the progress of said time interval; said audible time indicating devices comprising an alarm-sounding mechanism and reeds, said reeds mounted on said interval timer and disposed with free ends thereof intercepting the path of said sound-actuating arm;

each of said audible time indicating devices having a characteristic sound indicative of a specific time interval; said alarm-sounding mechanism being connected with said clock mechanism operable to sound an alarm at the conclusion of said time interval.

PRATHZER O. MELLARD.

REFERENCES CITED UNITED STATES PATENTS Name I Date Hutter Nov. 23, 1915 Number 

